> case study has shown that within 1 hour of fireworks displays levels of Strontium in the air increased 120 times, Magnesium 22 times, Barium 12 times, Potassium 11 times, and Copper 6 times more than the amount present in the air before the event. Strontium was found to be the best tracer in this study because it measured very high during the event and much lower at other time intervals which indicated that it was mostly a result of the fireworks display. > >Another study found that firework events brought air pollution spikes in suspended particles, Nitric oxide (NO), Sulfur dioxide (SO2), and created and dispersed an aerosol cloud hosting a range of metallic elements. The researchers found that although the "recreational pollution" from fireworks is transient in nature, the pollutants are highly concentrated and add significantly to the total yearly metal emissions and the particles are on average small enough to be easily inhaled which poses a health risk to sensitive individuals. > >Researchers have found that fireworks can create a burst of ozone which is an extremely reactive greenhouse gas molecule that can attack and irritate the lungs. The ozone is believed to be caused by ultraviolet light released by chemicals in fireworks... which in this study were sparklers > >http://www.geocities.com/yosemite/falls/9200/toxic_fireworks.html